A defiant Prime Minister Theresa May vowed Friday to form a new government to lead Britain out of the EU despite losing her majority in a snap general election and facing calls to resign.

“What the country needs more than ever is certainty,” May said.

The Conservative leader had called Thursday's vote in a bid to extend her majority and strengthen her hand in the looming Brexit negotiations, but her gamble backfired spectacularly.

Although winning the most seats, her centre-right party lost its majority in parliament, meaning it will now rely on support from Northern Ireland's Democratic Unionist Party (DUP).

May vowed to “fulfil the promise of Brexit”, in a statement outside her Downing Street office in London after seeking permission from the head of state Queen Elizabeth II to form a new government.

“It is clear that only the Conservative and Unionist Party has the legitimacy and ability to provide that."

“This will allow us to come together as a country and channel our energies towards a successful Brexit deal.”

Avoid a 'no deal'

The Conservatives and the pro-Brexit DUP are expected to team up on a vote-by-vote basis rather than enter a formal alliance after the stunning result left Britain with a hung parliament.

Sterling sank against the dollar and the euro on Friday as doubt was cast on the whole Brexit process. EU President Donald Tusk urged Britain not to delay the talks, due to start on June 19, warning that time was running out to reach a divorce deal to end four decades of membership.

“We don't know when Brexit talks start. We know when they must end. Do your best to avoid a 'no deal' as result of 'no negotiations',” Tusk wrote on Twitter.

May faced pressure to quit from opposition parties after a troubled campaign overshadowed by two terror attacks, but said Britain “needs a period of stability”.

'Lost confidence'

But Leftist opposition leader Jeremy Corbyn, whose Labour party surged from 20 points behind in the opinion polls, told May to quit, saying she had “lost votes, lost support and lost confidence”. Tory supporter Nick, 31, blamed the defeat on May's “arrogance”.

“It serves her right. Whoever takes over has to understand campaigning is important,” he told AFP in London.

With all but one constituency declared, the Conservatives won 318 seats -- down from 331 at the 2015 election -- while Labour was on 262, up from 229.

May, a 60-year-old vicar's daughter, is now facing questions over her judgement in calling the election three years early and risking her party's slim but stable working majority of 17.

'Mayhem'

The result is “exactly the opposite of why she held the election and she then has to go and negotiate Brexit in that weakened position”, said Professor Tony Travers of the London School of Economics university.

Newspapers reflected the political tumult, with headlines such as “Britain on a knife edge”, “Mayhem” and “Hanging by a thread”.

In a night that redrew the political landscape once again, the UK Independence Party (UKIP) lost millions of voters, triggering the resignation of leader Paul Nuttall.

The Scottish National Party of First Minister Nicola Sturgeon, which has dominated politics north of the border for a decade and called for a new independence vote after Brexit, lost 21 of the 56 seats it won in 2015.

Sturgeon said the result showed that “the reckless Tory pursuit of a 'hard Brexit' must now be abandoned.”

'Another layer of uncertainty'

May, who took over after the June 2016 Brexit referendum, began the formal two-year process of leaving the EU on March 29, promising to take Britain out of the single market and cut immigration.

Seeking to capitalise on sky-high popularity ratings, she called the election a few weeks later, urging voters to give her a stronger mandate.

Officials in Brussels were hopeful the election would allow her to make compromises, but this has been thrown into question by the prospect of a hung parliament.

“It creates another layer of uncertainty ahead of the Brexit negotiations,” said Craig Erlam, senior market analyst at OANDA currency traders.

Despite campaigning against Brexit, Labour has accepted the result but promised to avoid a “hard Brexit”, focusing on maintaining economic ties with the bloc.

Barely a month ago, the centre-left party seemed doomed to lose the election, plagued by internal divisions over its direction under veteran socialist Corbyn.

But May's botched announcement of a reform in funding for elderly care, plus a strong grassroots campaign by Corbyn which energised the youth vote, gave him momentum.

Britain has also been hit with three terror attacks since March, and campaigning was twice suspended. A suicide bomber blew himself up outside a pop concert in Manchester on May 22, killing 22 people.

Last Saturday, three assailants mowed down pedestrians and launched a stabbing rampage around London Bridge, killing eight people before being shot dead by police.